“ISIS is not an existential threat to the United States,” he told Atlantic correspondent Jeffrey Goldberg. “Climate change is a potential existential threat to the entire world if we don’t do something about it.”

Climate change is particularly worrisome, Obama said, because “it is a political problem perfectly designed to repel government intervention. It involves every single country, and it is a comparatively slow-moving emergency, so there is always something seemingly more urgent on the agenda.”

And climate change is probably helping fuel groups like ISIS, he said.

“Right now, across the globe, you’re seeing places that are undergoing severe stress because of globalization, because of the collision of cultures brought about by the Internet and social media, because of scarcities—some of which will be attributable to climate change over the next several decades—because of population growth,” Obama said. “And in those places, the Middle East being Exhibit A, the default position for a lot of folks is to organize tightly in the tribe and to push back or strike out against those who are different.”

Climate change will also likely create new refugee problems as arable land becomes more scarce.

“If you start seeing more severe drought; more significant famine; more displacement from the Indian subcontinent and coastal regions in Africa and Asia; the continuing problems of scarcity, refugees, poverty, disease—this makes every other problem we’ve got worse,” he said. “That’s above and beyond just the existential issues of a planet that starts getting into a bad feedback loop.”